Today's users of electronic instrumentation generally desire the measurement of either voltage or current to be highly linear over the range of the instrument (e.g., <<100 ppm over the range). Also, linearity can—and often does—drift with time and temperature, which may necessitate frequent corrections. And removing the instrument to a calibration facility or requiring external equipment is particularly undesirable.
Today's users also tend to desire having an option of making faster measurements with correspondingly lower accuracy [or slower high-resolution measurements when called for] with the same instrument.
Accordingly, a need remains for improvement in electronic instrumentation that does not affect throughput for lower resolution, high speed measurements (which is usually the case with multipoint calibration). However, while certain designs (e.g., dual converters) may begin to address this problem, the shortcomings associated therewith include increased cost with regard to board space as well as further complications to calibration traceability.